This is a Doppler effect. Generally, if you move to a frequency source, you would detect an increase in frequency and when you move away from a source you would detect a decrease.
For this question, before you pass them, you are actually approaching them, so you would hear a higher frequency than the constant 300 Hz they are playing at.
Using the condensed formula:
f ' = ((v <u>+</u> vd)/(v <u>+</u> vs)) * f
Where: vd = Velocity of the detector.
vs = Velocity of the frequency source.
v = Velocity of sound in air.
f ' = Apparent frequency.
f = Frequency of source.
v = 343 m/s, vd = detector = 27.8 m/s, vs = velocity of the source =0. (the flautists are not moving).
f = 300 Hz.
There would be an overall increase in frequency, so we maintain a plus at the numerator and a minus at the denominator.
f ' = ((v + vd)/(v - vs)) * f
f ' = ((343+ 27.8)/(343 - 0)) * 300
= (370.8/343)* 300 = 324.3
Therefore frequency before passing them = 324.3 Hz.
Cheers.
Answer:
Negative acceleration
Explanation:
Let us assume a vehicle is moving with a constant velocity u and then it comes to a sudden stop.
The initial velocity of the vehicle is u and finally it comes to rest, it means final velocity is 0.
As we know that,
Acceleration is equal to change in velocity divided by time taken.
We can see that the value of acceleration is negative. Hence, it leads to negative acceleration.
<u>Answer:</u>
Mass of combined products = 20.4 grams
Mass of combined product and Erlenmeyer flask = 136 grams
<u>Explanation:</u>
By law of mass conservation, mass cannot be destroyed or created. So mass before reaction is mass after reaction.
Mass of lead(II) nitrate = 15.6 grams
Mass of potassium iodide = 4.8 grams
Mass of the Erlenmeyer flask = 115.6 grams
Mass of reactants = 15.6 + 4.8 = 20.4 grams
So mass of products = 20.4 grams
Mass of combined product and Erlenmeyer flask = 115.6 + 20.4 = 136 grams
The answer is: To have easy access to a coolant for the reactor.
Hope this helps!:)
~Scarlett
